ungrateful daughter 😒

The problem is my mom an I don't get along. I live in TX she lives in NC and when she comes to visit she over stays her welcome! She was here when my 2nd was born and stayed 5 weeks! 5weeks! I've told her she can NOT stay that long again! So instead she thinks she can come for 2 weeks before the baby, Leave for 3 weeks then come back for when I'm scheduled to have her for "she doesn't know how long yet" I can NOT DO IT! I can't! I've told her to pick one but she continues to annoy and bring up coming both times.😞 

On top of all of this I want my "God" mother here instead, she can only come for 3 days day before during an after :) and would be gone so I think my mom coming to visit the day we come home from the hospital is better, she's going to die when I tell her that especially about my god mom, how do I tell her? Should I just suck it up and let her be here? How long is a REASONABLE amount of time??!